The section of that manual that you need is entitled "Description of Database Objects" or "Attributes of Cellviews" depending on the version you are using. For example, this is the "Cadence Design Framework II SKILL Functions Reference" or the "Virtuoso Design Environment SKILL Reference" manual. These should take you to the appropriate section in SourceLink:
There are lots of attributes listed, so I will not list them all here, but some common ones are bBox, cellName, cellViewType, instances, terminals, and shapes. Hopefully you are aware that these can be accessed using the ~> operator, or the dbGet() or dbGetq() SKILL functions, and set using the operator, or the dbSet()/dbSetq() SKILL functions.
The documentation should also be available as a PDF file, in this case under
Hopefully this answers your questions.